Preparation of microparticles composed of amphiphilic poly(γ-glutamic acid) through hydrophobic interactions

Abstract

A novel amphiphilic graft copolymer composed of poly(γ-glutamic acid) (γ-PGA) as a hydrophilic backbone and dodecylamine (DOA) as a hydrophobic side chain (γ-PGA-DOA) was successfully synthesized by employing 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) as the coupling reagent. The grafting degree was stoichiometrically controlled by adjusting the feeding amounts of DOA and EDC in the reaction system. γ-PGA-DOA, with a grafting degree of 55%, self-assembled via hydrophobic interactions and formed microparticles (MPs; diameter of 13±3 μm) in an aqueous solution. These MPs possessed functional carboxylic groups and could be further modified with compounds such as drugs, proteins and peptides, and thus have great potential as vaccine carriers. We report the preparation of novel functional microparticles by self-assembly of amphiphilic copolymer composed of poly(γ-glutamic acid) (γ-PGA) as a hydrophilic backbone and dodecylamine (DOA) as a hydrophobic side chain (γ-PGA-DOA). γ-PGA-DOA with a grafting degree of 55% self-assembled by hydrophobic interaction, and formed microparticles (diameter 13±3 μm) in aqueous solution. These microparticles possess functional carboxylic groups, and could be further modified with active compounds such as drugs, proteins and peptides, and thus have great potential as vaccine carriers.